Reshooting

Remember the sex scandal Kevin Spacey got in? All the Money in the World was going to feature him as J. Paul Getty, but got replaced by Christopher Plummer. The scenes he was in got re-shot. What does that mean to reshoot a scene featuring an actor who was either had to be removed because of death or a termination from the film by inappropriate actions?

Re-shoot basically means re-film. Every scene in which that character appears has to be filmed again, with the same other actors as before, same props, scenery, script, etc. The change must be invisible to the viewer.